Effects of stir-frying on the processing characteristics and in vitro digestion of oat flour during storage

Abstract

This study focused on stir-frying, a traditional Chinese method for treating oats before milling. The effects of stir-frying on the processing properties and in vitro digestion of oat flour during storage have not been explored. The results revealed that stir-frying treatment caused a greater amylopectin content of the oat flour, which made the oat flour easier to improve water absorption and expansion ability. The WAI of stir-fried oat flour was notably greater than that of raw oat flour, while the results of WSI were opposite. The enthalpy of gelatinization of the two oat flours increased significantly (p < 0.05) during storage, and the gelatinization characteristics changed significantly after 9 months of storage. SEM and CLSM studies showed that the dough made from stir-fried oat flour exhibited a well-formed gel network structure, better clumping performance and fat stability during storage. Compared with raw oat flour, stir-fried oat flour had a faster starch hydrolysis rate, a greater rapidly digestible starch (RDS) content, and a lower resistant starch (RS) content. The effect of storage time on the digestibility of stir-fried oat flour was less compared with raw oat flour. Overall, stir-frying improved the processing adaptability, digestibility, and stability of oat flour during storage.